A:AnswerIt uses standard parts but without upgrading the PSU, you likely could not add many more components to it. Primarily you would be limited to swapping existing parts.
A:AnswerYou could certainly run it on the high settings. With Vsync off, post processing and shadows turned down you could even get very high frame rates.
A:AnswerYou should not have much issue with streaming and playing the game. It may take some time playing with the settings in OBS or your streaming program of choice but it will work fairly well. You should be able to hit atleast 60FPS in game.
A:AnswerI would say it could run most games quite well. Upgrades to consider in the future would be a second generation Ryzen 5, perhaps 16GB RAM, bumping up to an RX 580, maybe a higher PSU like a 750W. But all of that is optional.
A:AnswerThis has an AMD Ryzen 3 processor. Intel is another manufacturer of Processors. While there are differences between the various models it is similar to a Ford vs Chevy comparison. Fans on both sides.